Manual

User’s Manual
Scott Edwards Electronics, Inc.
1939 S. Frontage Road, Suite F, Sierra Vista, AZ 85635 USA
ph: 520-459-4802 • fax: [phone] • www.seetron.com
BPP-420 • v4.0 • 2/03 • pg 6
Figure 5. Character code chart
Right-align Text (control-R, ASCII 18)
Accept a number from 2 to 9 (as text) representing the width of an area on the screen in which right-
aligned text is to be printed. Cursor will back up that number of characters from present cursor position.
Subsequent text will be stored without printing to the screen until one of the following is received:
• The specified number of characters.
• A control character (ASCII 1–31).
• A decimal point [the period (.) character, ASCII 46].
The display will print the text with right alignment and erase any leftover text within the specified width.
For example, move the cursor to the right end of the screen, send control-R (ASCII 18), followed by “5”
(ASCII 53), then “123” and Enter. The “123” will be printed right-aligned within the 5-character space.
Right alignment works only with the standard LCD character set, not with “big” characters (cntl-B).
Escape Sequences (control-[, ASCII 27, followed by additional parameters)
BPP-420 understands two instructions that begin with the escape code (ASCII 27).
• Define a Custom Character (ESC D n B0 B1 B2 B3 B4 B5 B6 B7)
The BPP-420 has eight custom-character slots. These characters are
mapped to ASCII codes 128 through 135. At startup, the unit loads
bitmaps into these slots for the big-character (cntl-B) mode. Using
the Define instruction, you can change a bitmap. Send Escape (ASCII
27) followed by the letter D (ASCII 68), then the symbol number you
wish to define (0—7, ASCII 48—55), followed by eight bytes defining
the bitmap. The contents of those bytes map to the custom character
as shown in figure 4.
NOTE: If you redefine any of the custom characters, you must restore
them using ESC E before using big-character mode.
• Restore Default Custom Characters (ESC E 1)
The big-character mode (cntl-B) builds 4-line-high characters using the custom-character bitmaps (ASCII
128 —135). If you use ESC D to redefine one or more of these characters, big characters won’t display
correctly. To restore the bitmaps needed for custom characters, use ESC E 1. That is, send ASCII 27 (ESC),
ASCII 69 (E), and ASCII 49 (1).
32 40 48 56 64 72 80 88 96 104 112 120 128 160 168 176 184 192 200 208 216 224 232 240 248
0
1
2
3
4
5
6
7
NOTE: ASCII 135–160 are blanks
To find the ASCII code for a given character, add the row and column numbers.
For example, capital D is in the column marked 64 in row 4, so its ASCII code is
68. Use the reverse procedure to determine the symbol for a given code. For
example, ASCII code 244 produces the symbol Ω, found at colum 240, row 4.
byte 0
byte 1
byte 2
byte 3
byte 4
byte 5
byte 6
byte 7
bit 0 (1) bit 1 (2) bit 2 (4) bit 3 (8) bit 4 (16)
Byte Values
1xx00000
1xx00100
1xx00010
1xx11111
1xx00010
1xx00100
1xx00000
1xx00000
128
132
130
159
130
132
128
128
binary decimal
Figure 4. Defining a custom symbol.
(see www.seetron.com for bitmap-design tools)
x is don’t-care bit